Improvement in valves for steam-engines



UNITED STATES JAMES E. THORPE, OF PROVIDENCE,

RHODE ISLAND, ASSIGNOR TO HIM- SELF, AND FRANCIS D. KIDDER, OF BOSTON, MASSACHUSETTS.

IMPROVEMENT IN VALVES FOR STEAM-ENGINES.

To all whom it may concern:

Be it known that I, JAMES E. THORPE, of the city and county of Providence, and State of' Rhode Island, have invented an Improved Duplex-Chambered Valve t'or Double-Acting Engine or Pump Cylinders; and I do hereby declare the same to be i'ull y described in the following specification and represented in the aecompanyin g drawings, of which- Figure l is a longitudinal section ot' such valve, its chest, seat, cylinder, and ports or connecting-passages thereof. Fig. 2 is an under side view of the valve.

The working-face of my valve, as well as that of its seat, is an arc of a cylinder whose center or axis is the center of motion ot' the valve. The valve shown at A in Fig. l has two chambers, c b, separated from one another by a partition, c, which is ot' more than sufficient size to cover the eduction or middle port ot the valve-seat B, such seat having three passages or ports, d ef, two of which, via-e ]'-eo1nmunicate with the ends ot the cylinder or pump-barrel C, while the other, d, leads into the eduction-chamber D.

l/Vhen the chamber a is directly over the ends of both passages e d, the passage c, lead ing to the bore of the cylinder, will be in communication with the eductioirconduit D. At the same time the passagef, leading to the said bore, will open into the chamber b, which also will open into the inductionchamber E,

in which the valve is situated, it being un derstood that when in use the said chamber E is a closed chamber, except in having communication with the generator or boiler from which it is to receive steam. So when by a movement ot' the valve the chamber b is car ried directly over the ends of the passages d and f, the passage f will be in communication with the eduction-eomluit D. At the same time the passage e will open into the chamber a., and such chamber c will open into the chamber E.

By means of the two chambers a b and the partition c, (the latter being of greater width or area than the middle port, 67,) there never can be any connection of the three ports c d f with each other so as to affect or destroy the vacuum of the cylinder.

It is well known that with a single-chambered oscillating valve having its seat and bearing-surface curved to the arc of a circle, it is very diflicult, if not impossible, to make the chamber so as to prevent, when the valve is in its central position, a communication of the three ports, particularly ai'ter the valve or its seat may have become slightly worn, but with the central partition and the two chambers, made and arranged with respect to the ports, as described, there is always such an overlap ot` the partition as will prevent any communication of the three ports, so as to materially affect, it' not destroy, the vacuum of the cylinder.

The vibratory movements ot' the valve are to be effected .by a suitable mechanism, such movements being properly regulated or timed to the movements ot' the piston ot' the barrel or cylinder.

I do not claim a vibratory or oscillatory valve made with a curved bearing and seat and a single chamber to operate with thrre ports ot' the seat; nor do I herein claim the valve made with two chambers and two planesurt'aced seats arranged at an obtuse angle, (as shown in the United States Patent No. 15,134, granted June 17, 1886, to J. C. King,) this latter valve, by reason ot' its peculiar construction and mode ot' operation, being continually liable to at't'ect or destroy the vacuum of the cylinder.

IVhat l claim as my invention or improvement consists In providing the valve with a single curved seat and a single corresponding bearing therefor, and with two chambers and a partition arranged in the valve as described, and three ports leading from the seat, and with the area or width of the bearing surface of the partition greater than that of the mouth ot' the central port, the whole being substantially as hereinbefore described.

Vitnesses: JAMES E. THORPE.

R. H. EDDY, F. P. HALE, Jr. 

